Process for bleaching molasses by means of electrolytic treatment



'is added. This liquor is then Patented Nov. 7, 1933 Q PROCESS MEANS roa BLEACHING Momssss air or ELECTROLYTIC TREATMENT Joseph William Thompson and John William Hinchley,-London, England No Drawing. Application April 13, 1931, Serial No. 529,788, and in Great June 2, 1.930

.2 Claims. (CL 204-4) This invention relates to a process for bleaching molasses by means of electrolytic treatment and the manufacture of yeast therefrom.

Residual liquors from beet and cane sugar manufacture, molasses and more particularly produced from them a dark colour also. Tins is objectionable because the colour of bread made with it is deteriorated.

bodiment of the process for producing substantially white yeast from beet sugar molasses.

Beet sugar molasses usually contains about 50% of sugars and must be diluted before treatment to reduce the viscosity and increase the surface tensionoi the solution. A convenient solution is obtained by diluting such molasses to contain about 15% of sugars. A still further dilution may be desirable with very dirty molasses. From to 1 per cent of sulphuric acid allowed to flow through a cell containing electrode plates which may be any material unaflected or only affected slightly by the liquor and the treatment. Graph-- ite or carbon plates are to be preferred. The electrodes are connected to a source of electromotive force the voltage of which is regulated to pass direct current through the cell at a density of about 1 ampere per square foot.

The acid is added to facilitate the process of electrolytic bleaching since the process would normally produce a certain degree of alkalinity. The current is maintained unt'l the mixture is bleached to a degree of approximately 60 per cent and then discontinued. The degree of bleaching may be estimated by means of a tintometer, that is to say, by comparing the color of the bleaching solution with ard solution bleached to a mately 60 per cent. The resultant filtered to remove anycarbon particles or other impurities suspended therein and finally ammonia, chalk or other suitable re-agent is added to neutralize the acid content. The liquor is then allowed to stand so that any precipitate formed may settle and the solution decanted.

further diluted and with the addition placed in a brewing tank of suitable yeast foods such as ammonium phosphate. Mother yeast is added that o! a standdegree of approxiliquor is then and air blown manner for the production 01 yeast.

It is neither desirable, economical nor necessary to completely decolourize the molasses to obtain a white yeast and the process stopped at a point where the rate or discharge of colour ceases for a time: usually when about 60 per cent of the colour is discharged. If the bleaching be carried further yeast poisons are be seriously attacked.

- Arw number of carbon plates may be placed in'the cell to serve as cathodes and anodes and connected to the source of-direct supply accordingly and since they are placed relatively close together they are prevented from short-circuiting by thin strips of non-conducting material suitably disposed.

Although one embodiment of the processhas been described by way oi example, variations in the proportions of the constituentoi the mixture to be treated may be made according to the character or quality of the molasses used. Furthermore, phosphoric or any other suitable acid may be used in lieu of sulphuric acid and similarly any suitable re-agent may be employed to neutralize the acid. All such variations in carrying out the process are intended to be included may be,

through the liquor in the usual tains about 15% of sugars, adding one-half to one 'per subjecting the mixture to electric current until the solution is bleached to a degree of about 60%, filtering the molasses to remove impurities, adding a re-agent to neutralize the acid content 0! the molasses, and

decanting'the solution from the precipitate i1 2. The process of bleaching molasses tor subsequent use in the production of yeast, which consists in diluting the molasses until it contains about 15% of sugars, adding /2 to 1% of mineral acid, passing the solutrodes, applying a direct current voltage to said electrodes suflicient to cause proximately 1 ampere per square foot to pass through the solution, maintaining said voltage until the solution is bleached to a degree of approximately 60%, filtering the molasses to re- 1 move impurities, adding a re-agent to neutralize 1 the acid The product of the process described may be wnmAM' THOMPSON.

HINCHLEY.

JOSEPH JOHN 

